The overall objectives are to discover how to attach substitution-inert metal centers to specific sites on molecules of biochemical interest, and to study the changes in reactivity and in other properties, which attend the coordination. When a solution of a complex of ethylglycinate N-bound to pentaammineruthenium(III) is acidified, rapid isomerization ensues with carboxylate replacing the amine group leading to ester hydrolysis. With a dipeptide, rearrangement to an amide bound form takes place, but peptide hydrolysis is not rapid. The chemistry is being explored in the hope that it may lead to a new facile method of end-specific peptide hydrolysis. Mixed valence molecules containing ruthenium(II) and ruthenium(III) bound to dipeptides and more complex peptide units are being prepared, in an effort to assess the extent of electron delocalization by studying the intervalence absorption. Dimethyl sulfide bound to ruthenium is readily oxidized in the presence of nucleophiles, in the simplest case yielding the dimethylsulfoxide complex of ruthenium(II). This chemistry is being explored as is the possibility that it will provide a means of producing energy rich phosphate bonds. The chemistry of osmium ammines coordinated to imidazole and other polar groups featured by biologically significant molecules is being explored.